Pikachu, The Mouse Pokémon. It occasionally uses an electric shock to recharge a fellow Pikachu that is in a weakened state.It raises its tail to check its surroundings. The tail is sometimes struck by lightning in this pose. This intelligent Pokémon roasts hard berries with electricity to make them tender enough to eat. If it looses crackling power from the electric pouches on its cheeks, it is being wary. It lives in forests with others. It stores electricity in the pouches on its cheeks.

Overview

Here we have Pikachu, one of the most famous animated characters in human history. In Red and Blue Pikachu was nothing special. It was just an easy way to get past Misty until you caught yourself something better like Electabuzz, Jolteon or Zapdos. Pokemon Yellow didn't really help Pikachu become any stronger. If anything it screwed Pikachu completely, preventing you from evolving the horrible little rat. In Gold and Silver however a new item was introduced. This item was the Light Ball, which doubles Pika's Special Attack. By doubling Pikachu's Special Attack (and eventually his Physical Attack) Pikachu became a fearsome offensive Pokemon with destructive capabilities comparable only to Mewtwo. Sadly offenses that rival the most powerful offensive Pokemon ever do not translate well when you consider that Pikachu has the defenses of wet tissue paper. It isn't very fast either... 90 base speed isn't great. Worse, its saving grace in Light Ball has become its downfall. Without the ability to hold another item Pikachu is only hitting about as hard as a Life Orb holder with 110 base offenses. Strong, but not really that dangerous. Problems aside Pikachu does still have the ability to hit very hard. In the lower tiers the number of things that can switch in on Pikachu is pretty minimal. It's also adorable!

Abilities

Static: The opponent has a 30% chance of being induced with PARALYZE when using an attack that requires physical contact against this Pokémon. Pretty cool, but keep in mind because of Pika's horrible defense any attack you take that isn't resisted will probably OHKO.
Lightningrod: Electric-type moves are drawn to this Pokémon. Electric-type moves will do no damage and the Pokémon's SP ATK is raised one stage instead. A great ability. An extra immunity is always good and the potential Special Attack boost can give Pikachu some pretty titanic offenses.

Specially offensive Pikachu is outclassed by most other electric types as they are generally faster, tougher and hit about as hard while holding Life Orb. Even Pikachu's evolution Raichu is probably better at Nasty Plotting. What Pikachu can do that basically no other electric type can do is strong physical electric moves. Pika's Volt Tackle is so powerful that it has about the same destructive capabilities as Zekrom's Bolt Strike. There is so much power here that few Pokemon will survive a neutral hit from it. Hidden Power Ice covers Dragon, Ground and some Electric types that Volt Tackle can't remove. Brick Break massacres the few things that survive your other attacks. Things like Bastiodon and Probopass. The last slot is sort of up to you. Substitute can reduce Pika's need to predict switch ins and protects against status. Encore is for those who live on the edge, locking your opponent into a setup, recovery or utility move. Volt Switch is cool to wear down your counters while doing acceptable damage off Pikachu's 274 base Special Attack. EVs are maxed in Speed and Attack to capitalize on the rat's ability to outrun a good portion of Pokemon and hit them as hard as possible. If you want to run Volt Switch consider running 176 Attack / 80 Special Attack / 252 Speed so Volt Switch has some more power behind it.

As said before Special Attacker Pikachu is worse than pretty much all other electric types. It does get Nasty Plot though, and ignoring Raichu and Plusle / Minun no other Electrics can use this. Pikachu is by far the most powerful of them and... the most frail. Try to scare off something and Nasty Plot. With a boost your Special Attack should near 800, more than enough to rip into nearly everything that doesn't resist it. Hidden power Ice, again, covers basically everything that Thunderbolt can't handle. Grass Knot smashes and Water / Grounds you may see as well as handling Camerupt, who needs to be very defensive and at full health to have even a chance at survival. EVs max Speed and Special Attack. You can run Signal Beam over HP Ice if you want to beat Grass types a little easier.

Pikachu has two main problems. One is its horrible defenses. It survives no hits, ever. This will not be fixed, even by evolving it to Raichu. The other problem is that Pika's 90 base speed isn't very good. Not terrible, but many things can outrun it. A recent event gave Pikachu a gift it could only dream of... Extremespeed. This event seems to have been forgotten about. Battle Simulators don't have it as a usable move, Smogon has no evidence of it and even Serebii doesn't have it listed in its Pokedex. Extremespeed off 332 Attack is strong, strong enough to do about 50% to most frail things like Cinccino. As with most Pikachu this set just spams attacks until it is forced out. But Extremespeed makes countering and checking Pikachu a lot more difficult. For example imagine this. You Thunderbolt and they switch in something faints. Great! But then they switch in Absol. Sucks huh? Now they can Sucker Punch for a OHKO... except you Extremespeed for 50% while the Absol Sucker Punches... which actually fails because Sucker Punch does not work if the target (you) uses a move with higher priority. Now the Absol must switch out or die, and Pikachu can continue its sweep. The rest of the moves on this set are here for the same reasons listed above. An important thing to mention is that this Pikachu event is limited to only using the ability Static, and Volt Tackle is impossible to breed on it.

Other Options

Surf, Rain Dance / Thunder, Brick Break, Volt Switch, Fake Out, Signal Beam, and Electro Ball.
First off let me say that Pikachu has almost the exact same movepool as Raichu, so I'm just going to copy / paste the same other options that Raichu has.
While not available yet, Surf will probably be released again as it has each other generation in some form. Surf doesn't really hit anything Grass Knot doesn't besides I guess Camerupt so even when it does become available it's not worth using.
Pikachu can use Rain Dance / Thunder but its too slow, and is largely outclassed by other Electric types at that. If Surf is available it might be a bit more useful however.Brick Break smashes Rock types but doesn't require Substitute or risk like Focus Punch does. It also breaks Reflect / Light Screen. Shame its only 75 base power, because that is very weak.Volt Switch is a lot of fun to scout out your counters and deal some damage to them. It doesn't hit very hard and Pikachu is worse at Volt Switch spam than more bulky electrics like Rotom and Luxray.
Though very weak, Fake Out can rack up some damage and even pair with Volt Switch get a few hits for free. Pikachu needs all four moveslots and a weak 40 base power attack isn't going to be pulling its weight like Grass Knot or Volt Tackle would.Signal Beam eradicates Exeggutor but doesn't really hit anything else.Electro Ball gets a mention just to say you should never use it. If you use Thunder Wave then Electro Ball you will have 150 base power against most things but if you're going to spend two turns for one attack why not Nasty Plot then Thunderbolt and hit for 190 base power?

Double & Triple Battle Options

Fake Out or Extremespeed pairs decently with Discharge. Pikachu is horrible in Doubles / Triples. It is so weak to priority that Weavile Fake Out can do 80% in one hit! A cute fun gimmick if you really want to, but nothing worth using.

Partners

Pikachu excels in breaking down walls so Pokemon that enjoy the opposing special walls being crippled or fainted are good choices. Exeggutor has good type synergy with Pikachu and can keep up the pressure with Sleep Powder + Leaf Storm. Rotom Fan form can Volt Switch freely if Pikachu eliminates annoying Golem and Golurks. Kadabra can take a team down almost single handed if Lickilicky is KOed or crippled from nasty Plotted Thunderbolts. Pokemon that have U-turn and Volt Switch are good partners as they can get Pikachu switched into the battlefield without taking a hit, which is important as the rat's defenses are almost non-existent.

Countering Pikachu

On paper not much. Bastiodon, Lickilicky, Regice, Regirock, and Cradily all stop Pikachu cold unless it runs Brick Break (or Volt Tackle in Regice's case). Without Grass Knot Pikachu has more trouble with Seismitoad, but no one really uses him. Gardevoir has trace to copy Lightningrod making it immune to Thunderbolt, but it falls instantly to and Pikachu with Static. Keep in mind most of the traditional Nasty Plot Pikachu counters fall immediately to the Physical Attacker. Basically any Pokemon faster than Pikachu can revenge kill it as its defenses are terrible. The list of Pokemon that can beat Pikachu despite not switching in safely is pretty large. Cinccino, Absol, Sawk, Braviary, Emboar, Swellow, Cacturne, Kadabra, Floatzel, Serperior and Skuntank all revenge kill Pikachu. If Pikachu runs Extremespeed many of those Pokemon may fail to revenge kill it at low health. Just be aware that Pikachu is more of a wall breaker than a sweeper. It will cut holes in your team so another Pokemon can sweep.

Wait... you actually want to use Pichu? Well, I can't really stop you, but it's your funeral. Aside from being outclassed by basically every other Electric-Type Pokemon in Little Cup, Pichu is the only Electric-Type Pokemon in the tier to get Nasty Plot which I guess makes it worth getting a set. Nasty Plot makes Pichu's pathetic 13/14 Special Attack stat boost to a decent 26/28. Encore gives you a chance lock Pokemon such as Bronzor and Lileep into Stealth Rock or other support moves, and other Pokemon like Magnemite into Electric-Type moves, so you can set up. Thunderbolt is a nice STAB move, that hurts many Pokemon (even if it isn't Super-Effective) after 1 Nasty Plot. Electric-Type Attacks hits a lot of Little Cup for at least neutral damage. Hidden Power Grass is needed for covering Pichu's awful move pool. It hits Ground-Types for Super-Effective damage, and can devastate Chinchou. You do miss out on hitting Lileep but Chinchou is more of a problem. Timid Nature should usually be used unless you don't care about being a little faster but every point counts when you're this frail. Focus Sash lets you survive a hit and either set up or get a guaranteed hit on the opponent. Life Orb makes you more powerful but that is cutting into Pichu's already short existence. Lightning Rod is a decent ability raising your Special Attack every time you get hit by an Electric-Type move. Other moves that you could use includes basically Volt Tackle and Toxic. Volt Tackle is another thing that makes Pichu stand out, and is powerful, but it doesn't suit Pichu as much as Nasty Plot. You can still use it if you want to run a Choice Band set as Pichu's Volt Tackle is the most powerful physical Electric move it Little Cup. Toxic can be used if you want to make Pichu a wall for some reason, but it's not that great because even with Eviolite, Pichu's defences still suck. Pichu basically falls flat with it's mediocre Speed and it's very bad bulk. Almost every Electric-Type Pokemon in Little Cup outclasses Pichu by a mile. Unless you have a really bad urge to use Pichu it's not that great.

Locations in Games

Ruby/Sapphire/Emerald: Safari Zone.

FireRed/LeafGreen: Viridian Forest, Power Plant

Colosseum/XD: Trade from Ruby/Sapphire/Emerald/FireRed/LeafGreen

Diamond/Pearl/Platinum: Trophy Garden.

HeartGold/SoulSilver: Viridian Forest.

Black/White: Evolve PichuTransfer from other games

Black 2/White 2: Evolve PichuTransfer from other games

Animé Appearences

Pikachu has made a tremendous amount of appearances. In most of its appearances, it has been with Ash on his journey through the various regions. However, other characters have used Pikachu including Richie, Volkner and Mewtwo